Notes on reading, on paper and on glass
A measure, a leading and a typeface walk into a column. Only one of them is usually blamed.
Reading on a screen is not reading on paper with the lights on. The differences are small individually and they compound, and almost all of them push in the same direction: a screen needs more air.
Contrast is not the same problem
On paper, ink is darker than anything a screen emits, and the page reflects the light in the room. On a screen the page is the light source, so pure black on pure white is harsher than the equivalent on paper. Most well-set screen text is not black; it is a very dark grey, and the reason is comfort rather than style.
The resolution argument is mostly over
For twenty years the honest answer to "why does this look worse on screen" was pixel density. That argument has largely expired: a modern phone resolves type better than newsprint. What remains is variability — the same page renders on a hundred different panels at a dozen brightnesses, and unlike a printed book you cannot tune for the medium because there is no single medium to tune for.
What actually helps
Slightly more leading than you would set in print. A slightly shorter measure, because a screen is read at a less predictable distance. And a size chosen for the worst case rather than the best: someone reading on a bus, one-handed, at arm's length.
None of that is exotic. It is the same craft, applied to a surface that moves.